1932. A mermaid costume with shells and pearls and drugstore jewels hides the scars on her legs, but it can’t hide the truth about her mother’s mysterious death.

Nattie is the star attraction of her father’s Prohibition-era paddlewheel that’s part speakeasy, part rumrunner. Celebrating a birthday, Nattie declares herself all grown up, done with the gawkers, crude jokes, leftover dribbles from gin fizzes, and waiting for a boiler room boy to make good on his promises.

As Nattie plots her escape, tensions mount, and so do tragic accidents.  A Polish nurse equipped with Old Country tonics is caught up in the turmoil as she tries to heal the wounds, old and new, while a fierce storm ravages the ship. Traitors are revealed, but the stolen loot remains hidden below deck.

1941. Nearly a decade later, the storm’s survivors are still clinging to weather-worn hopes. The nurse works stubbornly to redeem herself while the old captain fights for his sanity. Nattie’s mermaid act has moved to Chicago’s illustrious Rush Street. The stakes are higher, the threats more serious. As news of the treasure she lost in the storm emerges, along with new information about her mother, Nattie must fight the dark undertow with all her strength.

As the world marches to war, the dry-docked paddlewheel is commissioned by the US Navy to help train pilots. With a massive retrofit of the ship underway, time is running out. Nattie has one last chance to recover the lost diamonds—and her dignity.